N-Terminal dual protein functionalization by strain-promoted alkyne-nitrone cycloaddition.

Strain-promoted alkyne-nitrone cycloadditon (SPANC) was optimized as a versatile strategy for dual functionalization of peptides and proteins. The usefulness of the dual labeling protocol is first exemplified by the simultaneous introduction of a chloroquine and a stearyl moiety, two endosomal escape-improving functional groups, into the cell-penetrating peptide hLF (human lactoferrin). Additionally, we demonstrate that dual labeling of proteins is feasible by combining metal-free and copper-catalyzed click chemistry.

Protein enrichment by capture-release based on strain-promoted cycloaddition of azide with bicyclononyne (BCN).

An enrichment strategy was devised for azide derivatized macromolecules, based on strain-promoted alkyne-azide cycloaddition (SPAAC) and a cleavable linker. A ring-strained alkyne, bicyclo[6.1.

Collagen targeting using multivalent protein-functionalized dendrimers.

Collagen is an attractive marker for tissue remodeling in a variety of common disease processes. Here we report the preparation of protein dendrimers as multivalent collagen targeting ligands by native chemical ligation of the collagen binding protein CNA35 to cysteine-functionalized dendritic divalent (AB(2)) and tetravalent (AB(4)) wedges. The binding of these multivalent protein constructs was studied on collagen-immobilized chip surfaces as well as to native collagen in rat intestinal tissues.